The running theory I have going now after watching last week's episode where Hurley could see Jacob but no one else could him is that the same thing happened to Ben. Jacob was around Ben this whole time giving Ben instructions. Only no one could see Jacob except Ben.
But, again, I've been wrong before. SMOKEY!!!
Anyway, someone posted this on Fark and, frankly, this is one the best LOST parodies going. It's just so silly. So here it is, LOST - The Vocalize Remix Enjoy.
The original Vocalize video. If you can stomach to watch it again. I swear, you will get this song stuck in your head.